Overview of Avian Botulism Diagnostic Testing in 2024–2025
Yu-Hua Shih
Abstract
Avian botulism is caused by neurotoxins produced by Clostridium botulinum and is one of the important causes of mortality in migratory birds and waterfowl. Among avian cases, toxin types C and D are the most commonly reported. This study summarized suspected avian botulism cases submitted to the Disease Diagnostic Center of our institute during 2024 and 2025 to understand the occurrence of avian botulism and the distribution of toxin types in wild birds in Taiwan. During the study period, a total of 181 suspected cases were received, of which 47 (26.0%) tested positive. In 2024 and 2025, 113 and 68 cases were submitted, respectively, with 31 and 16 positive cases, respectively. Diagnostic methods included mouse inoculation tests and molecular biological assays. Among these, 11 serum samples were positive for botulinum toxin by mouse bioassay, while the remaining 36 cases involving dead birds or organ samples were tested by molecular methods for toxin genes and toxin typing. Positive cases were mainly distributed in coastal wetland areas of Tainan City, Chiayi County, and Kaohsiung City, with black-faced spoonbills accounting for the majority (22 cases), followed by pied avocets and grey herons. Cases occurred mainly from November to March of the following year. Toxin gene typing results showed that 21 cases (58.3%) were type C and 15 cases (41.7%) were C/D mosaic type. The results indicate that avian botulism remains a significant threat to migratory birds and waterfowl populations in Taiwan. The compilation of diagnostic cases and pathogen analysis can enhance understanding of the occurrence and toxin type distribution of avian botulism in wild birds in Taiwan and provide a reference for related disease prevention and control measures.
Evaluation of the Effects of Probiotic Complex on Gut Microbiota, Antimicrobial Resistance, and Health Care in Nursery Pigs
Nan-Ling Kuan
Abstract
This study explores the feasibility of using probiotic complexes as alternatives to antibiotics during the weaning period in piglets. A total of 36 healthy piglets participated in the 4-week feeding trial, divided into three groups: additive-free (group A), probiotics (group B), and antibiotic growth promoters (group C). The research evaluated the effects on gut microbiota composition, diversity, and antibiotic-resistant strains. The research evaluated the effects on gut microbiota composition, diversity, and antibiotic-resistant strains. Salmonella sp. was not detected in any of the groups, highlighting the maintenance of high hygienic conditions. Both the probiotics and control groups showed greater microbial diversity and increased abundances of beneficial genera such as Lactobacillus and Prevotella. Notably, the probiotics group exhibited the lowest levels of antimicrobial resistance, reflecting a decreased isolation rate of extended-spectrum β-lactamase - producing E. coli (ESBL-EC), although the reduction was not statistically significant. In contrast, the antibiotics group presented a less diverse microbial profile alongside elevated expression of multidrug resistance genes. These results indicate that probiotics support gut health in piglets and can help mitigate the risks of antimicrobial resistance. To optimize animal health and reduce the emergence of resistance, farms are encouraged to find a balanced approach in deploying both probiotics and antibiotics.
Report on Participation in Foot and Mouth Disease Diagnostic Techniques Training in the United Kingdom
Cheng-Ju Pan
Abstract
The World Reference Laboratory for Foot and Mouth Disease (WRLFMD), established at The Pirbright Institute (TPI) in the United Kingdom, is an international reference laboratory of the Food and Agriculture Organization of the United Nations (FAO) and the World Organisation for Animal Health (WOAH). It has long been responsible for critical global functions including pathogenic characterization, serological testing, molecular epidemiological analysis, diagnostic assay development, and international technical support for foot and mouth disease (FMD), serving as a core institution in the global FMD control system. Taiwan has established a range of FMD diagnostic methods, including virus isolation, nucleic acid detection, enzyme-linked immunosorbent assay (ELISA), and virus neutralization test (VNT), which are sufficient to support current diagnostic, surveillance, and emergency response needs. However, considering the continued circulation of serotype O and A FMD viruses in neighboring regions, as well as the recent emergence of serotype SAT1 outbreaks, the importance of strengthening diagnostic capabilities for multiple FMD serotypes has become increasingly important. Through this training at the TPI, the laboratory diagnostic capacity for addressing the risk of incursions of exotic FMDV will be strengthened.